In many instances, it is necessary to locate a position indicating structure with respect to a work piece which is to be milled, sanded, ground, etc. The precision and stability of the positional device is important, as is the ability to re-position the positional device. In computerized machinery, the computer needs to know exactly where the work piece is located in order to precisely operate on the work piece. In older machinery, individual components which either located the work piece, or even which were general supports needed to be bolted down, requiring worker intrusion into the work area. Improvements to the work area enabled the use of a vacuum to hold down work piece supports and locators so that they could be more quickly moved or moved using hooks or poles where necessary from outside of the work area. Where the work pieces are not required to be specifically placed, such as a general support, the use of a pole or other distance manual device allows the worker to remain outside of the work area and push the supports about the table. This is very difficult and increases in difficulty where the general supports have significant weight. Even where a general support is only a few pounds, movement across a table can be difficult. If difficult for use with general supports, the precise locator supports simply cannot be manipulated without the operator getting into the work area of the machine. However, movement of the supports or other structures for specific exact placement are virtually impossible to accomplished by a worker from the edge of a work zone.
Even the best method of location, described in issued U.S. Pat. No. 5,562,276, to the inventor herein, discloses the use of an angled device which can be machine located, with a worker placing a vacuum hold down locator against the angled device to insure that the locator is exactly positioned. For this to occur, the worker still must be in a position to visually assure that the locator is precisely located. The vacuum can then be remotely applied to hold the locator down, but where the worker must crawl into the process space each time, the full effectiveness of the use of vacuum hold down during machine set-up is not realizable.
The content of U.S. Pat. No. 5,562,276 is incorporated herein by reference. This was a major advance in machine locator technology, since it enabled the locators to be automatically raised to enable location of the work piece, and automatically lowered to enable work to be done on the work piece. However, the human operator was still required to manually go onto the table to make certain that the locator was positioned precisely on the angled device.
Currently, and especially in the material grinding industry (including glass, granite, marble and the like), a variety of edge configurations are available, with these complex shapes being ground by a router-type spindle which travels around a work piece. The locator of the U.S. Pat. No. 5,562,276 has a pneumatic operator which rises to enable entry of the work piece to a position tangentially abutting a stop surface of the locator device. After locating the work piece by abutting it against a stop surface of the locator, the stop surface is pneumatically lowered to permit grinding work to be done on the work piece. Where a number of runs of the same type of material generally is to be done, the locators can be left in place, raised as the new material is loaded and the stop surface lowered when the material is being processed.
Particularly with machines having larger and more powerful grinding devices and which act upon larger work pieces, the locator devices need to be larger, have larger bases to oppose a tilting force from the work piece as it is being positioned. The need for increased size and more stable work pieces makes physical placement even more onerous. Workers thus spend even more time within the process machinery positioning the material locators, which requires exact location such that the process machinery will register the location of the work piece positioning stop device.
In addition, for different runs of different material, re-positioning of the pneumatic locator devices, regardless of size, requires the precise re-positioning of the locator devices. This precise re-positioning takes significant amounts of time. Given the high cost of the process machinery, loss of time and money occurs during change in setup, making the unit cost of a particular run configuration setup quite high. Lowering the time and effort required in changeover will significantly lower the cost of making short runs of material. The ability to make less expensive short runs is valuable, especially where other cost factors in the distribution channel naturally favor short runs, so long as the short runs are of modest additional cost. Thus the cost savings of short run setup ripple through the vertical distribution system.
The limitation most encountered in process machinery is the limitation of the main robotic member, typically a spindle or rotational driver having little complex robotic capability. The main capability of the main process member relates to its locational ability, rotational orientation locatability and perhaps one or two other control aspects. In the case of material cutting and polishing machinery, for example, the main robotic member has the ability to select tools, rotationally orient to pick up to rotate to grind and also the ability of a single on and off pressurized air source. The manipulability is thus limited. Utilization of the existing robotic translational capability to the greatest extent possible to eliminate the need for workers to enter the work process space is highly desirable. What is therefore needed is a method and device which will harness the existing robotic ability of the process machine to enable placement of position locators precisely, but without costly additional robotic positioning and manipulation equipment.